SCADA (supervisory control and data acquisition) is a category of software applications for controlling industrial processes, which is the gathering of data in real-time from remote locations in order to control equipment and the operating process conditions.
In this post, we are going to learn how to establish a connection between SCADA software and any device that has the ability to communicate over the Modbus protocol.
Professor Jose Soares Augusto explains the meaning of a SCADA driver that it is a low-level software component, usually written in C or even in assembly language, whose main function is to “link”, or integrate, an external hardware or software component into the system.
In a PC operating system, you have drivers for “video cards”, for “audio cards” for the USB protocol, etc.
The SCADA driver usually is a “satellite” component in the operating system software of a device that needs to connect to an industrial (the main area of deployment of these systems) SCADA network.
Notice that the methodology of working for a Driver is kindly different from the Server principle of working.
A driver is something related to hardware. It basically contains a mapping/translation so that an operating system can communicate with the hardware.
Client and Server, on the other hand, are related to each other. In the simplest terms, a client is an application that takes input, sends data to a Server to be processed, gets returned information, and presents the output.
Creating a new project as shown in Fig. (1).
To establish the Modbus driver, we have to go to the Communication list at the project explorer as shown in Fig. (2).
Then to add the driver right click on the driver folder in the project tree that is shown in Fig. (3) and select Add Driver.
The driver’s window will pop up as shown in Fig. (4) now you can choose the suitable driver for your controller or your interfacing hardware.
As shown, we select the Modbus RTU driver via TCP, then you have to press select to add it to your project drivers and OK.
Now as shown in Fig. (5) the Modbus driver is successfully loaded to your project and by clicking on the Main driver sheet you can setup the driver parameters and tags.
To configure the MAIN DRIVER SHEET, right-click on the icon, and select Open from the pop-up, or just double-click on the icon.
The MAIN DRIVER SHEET worksheet is divided into two areas:
Description field: Type a description of the MAIN DRIVER SHEET for documentation purposes.
Disable field: Type a tag or an expression to enable and disable the communication of each MAIN DRIVER SHEET on the fly.
Read Completed field: Type in a tag and the communication driver toggles the tag when it completes a read command.
Read Status field: Type in a tag, which is updated with the status of the last read command.
Write Completed field: Type in a tag and the communication driver toggles the tag when it completes a write command.
Write Status field: Type in a tag, which is updated with the status of the last write command.
Min and Max checkbox: Click (check) to specify minimum and maximum values for data from the field equipment.
Min and Max fields (become active only when you enable the Min and Max checkbox): Type a range of values, which can be converted into an engineering format.
Tag Name field: Type the name of a project tag to be used by the communication driver.
Station field: Type the number of the equipment station within the network. The syntax in this field varies with each communication driver.
If you’ve configured the driver to do serial encapsulation via TCP/IP or UDP/IP, then the station may be specified using the following format “IP_address: port_number: station”
I/O Address field: Type the address of the field equipment related to the project tag. The syntax in this field varies with each communication driver. Refer to the appropriate driver’s documentation for further information.
Action field: Specify the communication direction, using one of the following options:
Scan field: Specify the condition under which the tag value is read from the remote device or server and then updated in the project database, using one of the following options:
This option is recommended for tags that must be continuously monitored in the background, such as tags that trigger alarms, tags used in recipes, tags that are recorded in the historical database, and so on.
This option is recommended for tags that are used in screen objects, because the project may not need to update tags that are not being visualized anywhere. Selecting this option can improve project performance.
NOTE
If you are not sure of which option to select, select Always. This will guarantee the tag is read and updated.
If you liked this article, then please subscribe to our YouTube Channel for Electrical, Electronics, Instrumentation, PLC, and SCADA video tutorials.
You can also follow us on Facebook and Twitter to receive daily updates.
Learn the example of flip-flop PLC program for lamps application using the ladder logic to…
In this article, you will learn the STAR DELTA programming using PLC controller to start…
Lube oil consoles of rotary equipment packages in industrial process plants are usually equipped with…
Rotating equipment packages such as pumps, compressors, turbines need the lube oil consoles for their…
This article explains how to blink lights in ladder logic with a detailed explanation video…
In this article, a simple example will teach you the conversion from Boolean algebra to…